Adjustable spring clamp



Jan. 16, 1951 F R. DORNER ADJUSTABLE SPRING CLAMP Filed March 23, 1949 ,4 r rash/Er Patented Jan. 16, 1951 UNITED STATES *PATENT OFFICE V j V w I 2,538,509 V ADJUSTABLE SPRING CLAMP 7 Fred R. li)orn'er, Middletown, Ohio Application March 23, 1949, Serial No. 82,965

Claims,

This invention relates to an adjustable spring clamp or clasp; and more particularly to a clasp embodying two gripping jaws formed of sheet material." i

It is the object ofthe presentiinvention to provide a rugged'cla'mp of'sheet metal composed of but few parts and which may be fabricated economically. v It is a further object Ofthe invention to provide-a clasp composed of 'two relatively movable jaws which are capableof 'a'wide range of separation therebetween, and a camming member for resilientlypressing one of said jaws towards the other in a manner-to secure a tight clamping. of the material'between the jaws at all p0- sitionsof separation therebetween.

It is a further object of the invention tocombine two-relatively movable jaws with a .cammin pressing member insuch a manner that the resulting clamp remains efiective over :a longperiod' of time without wear or deterioration ofithe parts or reduction in theeifective clamping action between the jaws. s

It is a further object of the invention to provide a clamp which couples the cam actuator with the movable jaw in order to provide a convenient handle for the latter as the same is moved toiits varying positions and until such time as the cam becomes effective to exert its clamping action.

' The invention proceeds upon the principle of providing a clamp formed of a base jaw and movable jaw pivoted thereto by means of a reentrant portion on the latter terminating in lateral extensions which actias trunnions rotatable'in circular openings formed in upstanding wings at the rear portion of the base jaw. The trunnions are operative along a chordal section of the circular or cylindrical portions of the wings, which merge into the main portion of the movable jaw which is adapted to be flexed into pressing engagement against the material disposed between the jaws by the operation of a camming member trunnioned .in the upper portion of the circular openings in th above-mentioned wings. These camming trunnions are of greater width than thickness so that as said cainming member is rocked approximately 90 .to lock the clamp, the

greater dimensions of the width act upon the main surface of the movable jaw to firstly fix the trunnions of the movable jaw within the circular bearings in the wings and thereafter press the latter towards the trunnions in the direction of the base jaw to effect a tight clamping of the As an additional refinement, "the cam actuator is provided with a springmember adapted to releasably engage the rear extremity of the movable'jaw so that the latter is moved with the camming member for all free movements'of these parts and until such time as the camming member is swung to exercise its camming and clamping action. 1 1

Other objects and purposes will appear from the detailed description of the invention following hereinafter, taken in conjunction with the accompanying drawing, wherein Fig.1 is'a perspective view of the clamp assembly operative on a stackof sheets;

Fig. 2 is a plan view of the clamp;

Fig. 3 is a front elevation of the clamp-in released position with parts thereof shown in dotted lines to indicate the free movement of the movable; clamp and the cam actuator;

Fig. 4 is a front elevation of the clamp in its efiec'tive'clampin'g position; 7

Fig. 5'is an'exploded view in perspective of the three constituent elements of the clamp assembly;

Fig. 6 is a frontelevation of a second embodiment of the invention'presenting an additional refinement for facilitating the movement of the upper jaw by the cam actuator; and

Fig. 7 is a perspective view of the camactuator shown in Fig. 6.

' In the drawings, the clamp in accordance with the present invention is formed of two relatively movable jaws comprising a base member ID adapted to have upstanding wings I l at the rear portion thereof which may be stamped and bent from the planeofthe member Hi, and a movable spring jaw l5. Circular openings I 2 are formed in the upstanding wings I!) which provide bearings for the pivot members of the movable jaw and cammingv elements as described below.

. The movable jaw 15 is formed of spring metal I having a downwardly bowed ortion H) at the materialadapted to be disposed between the jaws.

front thereof and a reentrant portion at the rear which is turnedat pointlt and terminates at edge 11. The main portion of the movable jaw i5 is accommodated between the upstanding wings ll while the downturned extremity thereof at edge I! is provided with lateral extensions 18 which are adapted to engage within the openings l2 and act as trunnions for the rotary move.- ment of the movable jaw I5 relative to the base lll.- These extensions I8 are smaller than the diameter of the openings l2 and are disposed upon a chordal line of each opening and may vary from a horizontal line; as shown in Fig. 3 to a greater width than thickness, so that when such extensions are disposed as shown in Fig. .3, the movable jaw is freely movable to any position, which is permitted by the movement of the trunintermediary of the cam plate 32 until the latter begins to exert its camming action.

As shown in Fig. 5, the component parts of the clamp are of simple design which may be stamped out easily and shaped as shown at minimum cost. The assembly of the parts may be effected by springing them into place.

While I have described my invention as embodied .in a specific form and as operating in a specific manner for purposes :of illustration, it should be understood that I do not limit my invention thereto, since various modifications will suggest themselves to those skilled in the art without departing from the spirit of my invennion extensions I8 and cam extensions 2:! therein. For any predetermined spacing between the jaws, as determined by the thickness of the material therebetween, a turning movement of the camming member 22 in a clockwise direction approximately 90 effects a turning of the extensions 21 from the positionshown in Fig. 3170 that shown in Fig. 4 to resiliently press :movab le .jaw l5 towards the base H), which serves first to has the trunnions 48 in their set position and there-'- af-ter to press downwardly on movable jaw towards the trunnions l8 and tip l9 towards the base NJ, to clamp the material 5P tightly therebetween. The effective iforcelon the camming extensions 2] is increased by the moment arm atforded by the offset between the plane of the actuator 22 and the plane of the cam extensions 2| as well as bythe length of the former.

Disengagement of the material between "the jaws of the clamp maybe effected quickly by a turning of the cam plate 22 from the position shown in Fig. 4 to that :shown in :Fig. .3.

In the modified embodiment of the invention shown in Figs. :6 and 7,, thecam.-actuator plate 32 extends directly from the transverse cam bar 231.) with the -cam-.extensions 3!. These extensions 3| are :of less thickness than width in order to enable the 'camming force to be exerted :upon the movable jaw [5 as the plate .32 is turned from a the position shown in full lines in Fig. 6 .to clamping position, indicated in dotted lines, tor a .pad of material P. A spring retainer .34 mounted :on the outside face of cam actuator 32 .by means of a rivet .35, and provided with a hook extremity .316 at the tree end thereof, serves to .releasably couple the cam actuator 32 with the movable jaw 15 ,by the convexity 3.6 yieldingly engaging the .end I-B of the movable jaw. Thereby the .movement of the jaw .l 5 may be effected by the turning movements of the cam plate 32 between its limiting positions when the free end of the jaw 15 is in contact with the base I?) to the maximum raised position of the movable jaw at nearly right .angles to the plane of the base I'll. Thus,the .cam actuator may be moved from the position shown in full lines in Fig. '6 to engage the material P and thereafter upon blocking of the movement of the movable jaw by the presence of the ,mate rial -P therebetween and jaw I I], the actuator plate 32 continues-its rotary movement 'ina clockwise direction w'ith the disengagement of the hook retainer '36 from the curved end it in order to permit the cam extensions M to come into play within the upper portions of the bearing openings l 2 to exert the pressin action on the movaole jaw l5 as explained above in conjunction" with the first embodiment of the invention. This constructional expedient facilitates the movement-of the jaw 15 which is effected through the tion, the scope of which is set forth in the annexed claims.

i-claim: I I

1.,A clasp comprising a base member having a gripping portion at the forward part thereof and a pair of upstanding wings on the lateral sides of the rear part thereof provided 'with aligned circular bearings, a movable jaw 11001)- erating with said base member formed of a reentrantly shaped rear portion and a downwardly extending torward portion adapted to cooperate with the gripping portion of :said base, the portion of said movable jaw being narrower than the spacing between said wings with the :downward-1y turned rear end portion provided with lateral extensions fitting witlriin [said circular bearings, and .a .camming member provided with lateral .ex-tensions pivotally mounted within said circular bearings within the upper portions thereof and above the upper surface .of said movable jaw to effect a clamping movement of said movable jaw in one direction of rotation of said cammingmemben.

12. A 2013.513 comprising ;a base member having a gripping portion at the .io-rwa-rd part thereof and .a pair of upstanding wings on the lateral sides of the rear part thereof provided with aligned circular bearings, a movable jaw coopcrating with said base member tor-med of a reentrantly shaped rear portion and a downwardly extending forward portion :adapted to cooperate the gripping portion :of said base,the mam portion of said movable j aw being narrower than the spacing between said wings with :the downwardly turned rear end portion provided with lateral extensions fitting within said circular bearings, and a camming member provided with lateral extensions pivotally ;mo11-nted within and circular bearings within the upper portions thereof and .above the upper surface of said movable jaw, said extensions being of a greater width than thickness so that as said cam :is rotated from a position iTl'Whl Ch said extensions are :par- 'allel to the upper face of said :movable jaw to a position transverse thereto, said movable jaw is "urged into clamping engagement with said base member; Y

3. A clasp comprising a base member having a gripping portion at the forward part thereof and a "pair of upstanding wings on the lateral sides of the rear part thereof provided with aligned circular bearings, a movable jaw cooperating with said base :member formed of .a reentrantly shaped rear portion .and downwardly extending forward portion adapted to cooperate with the gripping portion of said base, the main portion of said movable jaw being narrower than "the spacing between said wings with the downward'ly turned rear end portion provided with lateral extensions fitting within said circular bearings along a chorda'l line therein, and a-cam ming member provided with lateral extensions pivotally mounted within said circular bearings within the upper chordaliportions thereof and above the upper surface of said movable jaw, said extensions being of a greater width than thickness so that as said cam isjrotated from a position in which said extensions are parallel to the upper face of said movable jaw to a position transverse thereto, said mgvable jaw is urged into clamping engagement with said base member.

4. A sheet metal clasp comprising a base member having a gripping portion at the forward part thereof and a pair o f. ,upstanding wings on the lateral sides of the rear part thereof provided with aligned circular bearings, a movable jaw cooperating with said base member formed of a reentrantly shaped rear portion and a bowed forward portion adaptedto, cooperate with the gripping portion of said base, the main portion of said movable jaw being-j; narrower than the spacing between said wings,.with the downwardly turned, end portion provided with lateral extensions fitting within circular bearings along a chordal line therein, and a camming member formed of an operating plate and a, pressing bar normal thereto provided with lateral extensions pivotally mounted within said circular bearings within the upper chordalp'ortions thereof and above the upper surface of said movable jaw, said extensions being ofa (greater width than thickness so that as said cam is rotated from a position in which said extensions are parallel to the upper face of said movable jaw to a position transverse thereto, said movable jawis urged into clamping engagement with said base member. I

5. A clasp comprising a base member having a gripping portion at the forward part thereof and a pair of upstanding wings on the lateral sides of the rear part thereof provided with aligned circular bearings, a movable jaw coopcrating with said base member formed of a reentrantly shaped rear portion and a bowed forward portion adapted to cooperate with the gripping portion of said base, the main portion of said movable jaw being narrower than the spacing between said wings with the downwardly turned end portion provided with lateral extensions fitting Within circular bearings along a chordal line therein, a camming member formed of an operating plate and a pressing bar normal thereto provided with lateral extensions pivotally mounted within said circular bearings within the upper chordal portions thereof and above the upper surface of said movable jaw, said extensions being of a greater width than thickness so that as said cam is rotated from a position in REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 297,667 Brown Apr. 29, 1884 613,816 Harrison Nov. 8, 1898 1,218,276 Klein Mar. 6, 1917 1,651,435 Bernstein Dec. 6, 1927 

